Searching for New Components in Non-Keplerian TNO Binaries

Many Trans-Neptunian Objects (TNOs) are known to be composed of multiple components, such as the ~100 TNO Binaries that have two known components. Only the Lempo, Haumea, and Pluto systems have 3, 3, and 6 confirmed components at present. Such TNO systems with several components are particularly valuable for understanding the formation and evolution of TNOs; for example, the alignment between the mutual orbits in these systems is an important formation diagnostic. Our group is exploring a new technique to detect additional components in TNO Binaries: significant deviations from the Keplerian motion expected in two-body systems. MultiMoon — a Bayesian parameter inference tool for non-Keplerian motion of small body binaries — has been used to analyze all TNO binaries with well-known orbits. MultiMoon has identified several TNO Binaries that show significant non-Keplerian motion potentially consistent with unknown components. We investigate the detectability of these unknown components in existing HST data. We employ a new software package called nPSF that performs Bayesian parameter inference on fitting multiple PSFs to HST images. We will discuss implications of our search on the properties of TNO systems.